The following summary was adapted from a RefComm Galveston 2024 Keynote Presentation given by Stephen Klejst, Executive Director, and Melike Yersiz, P.E., Chemical Incident Investigator of the U.S. Chemical Safety and Hazard Investigation Board. The full PDF presentation can be downloaded below.
At the 2024 RefComm Galveston keynote address, CSB Executive Director Stephen Klejst and Chemical Incident Investigator Melike Yersiz provided in-depth analyses of four case studies in which there were accidental release events at U.S. refineries. This presentation provided real value to refiners from around the globe, who were able to learn from these events– not only so they can avoid making the same mistakes in their own units, but also so they can put in place protocols to make their work environments safer for plant employees.
The four case studies covered were:
Philadelphia Energy Solutions, Philadelphia, PA, June 21, 2019
TPC Group, Port Neches, TX, November 27, 2019
Husky Superior Refinery, Superior, WI, April 26, 2018
Intercontinental Terminals Company (ITC), Deer Park, TX, March 17, 2019
In each case, Mr. Keljst and Ms. Yersiz provided an incident summary, an overview of the safety issues at play, the actual causes of each incident, and the CSB’s recommendations.
Common causes of process incidents:
Management system deficiencies
- poor program to implement PHA action items
- ineffective procedures
- hazards not understood or controlled at company level
- poor control of reactive hazards
Equipment failures due to damage mechanisms
- sulfidation corrosion
- HF corrosion
- high temperature hydrogen attack
Overview of the Philadelphia Energy Solutions Incident, 2019
- Fire and multiple explosions
- six injuries
- A pipe elbow in the hydrofluoric acid (HF) alkylation unit ruptured.
- A large vapor cloud engulfed the unit.
- The vapor cloud ignited about two minutes after the start of the release, causing a large fire followed by multiple explosions.
Safety issues
- Mechanical integrity
- Verifying safety of equipment after changes to RAGAGEP
- Remotely operated emergency isolation valves
- Safeguard reliability in HF Alkylation units
- inherently safer design
To read the full report on this incident by the CSB, including the cause, and details on the other three events, click the link below:
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